JAKARTA — Indonesian officials said 384 people were killed and many more remained unaccounted for after an earthquake of magnitude 7.5 on Friday evening triggered a sundown tsunami measuring between five and ten feet high that washed over Palu and Donggala, two coastal cities in Sulawesi in the east of the Indonesian archipelago

Earlier on Saturday Sutopo Nugroho, the disaster mitigation agency spokesman, told media in capital Jakarta that the deaths had been tallied from four hospitals in Palu, population c.a 380,000, and that there were likely to be “many [more] victims,” possibly including hundreds of people who were attending a beach festival when the waves hit.

Among the dead was Anthonius Gunawan Agung, a young air traffic controller who died after leaping from a damaged airport navigation tower in Palu, after ensuring a commercial flight took off before the disaster hit. Mr. Anthonius was lauded across Indonesia as a hero for his actions.

The latest death toll did not include the town of Donggala or other stricken areas outside Palu, the central Sulawesi regional capital.

Images from the stricken area, some relayed by the disaster mitigation agency and some posted on social media or disseminated via messaging applications, showed a wave slamming into the coast along Palu after the Friday evening earthquake. Terrified onlookers observed the approaching water from the upper reaches of a coastal building, turning to flee in terror as the water rolled up the shoreline and surged to an apparent 10 feet high, nearly swamping the vantage point.

Ensuing footage showed a damaged mosque — a recognisable local landmark — as well as campaign posters for national elections scheduled for April next year. Other images posted overnight showed lines of dead bodies, debris, damaged buildings and sodden streets.

Aulia Arriani, the head of communications at the Indonesian Red Cross, said that colleagues on the ground described scenes of chaos, including “lots of collapse[d] buildings, [damaged] homes and streets, dead bodies.”

Comprehensive and accurate numbers of dead and injured were proving difficult to establish as relief workers raced to access the stricken region despite mangled communications and transport infrastructure. “I’m afraid there are still people under the collapsed buildings,” said Aulia Arriani.

Indonesian President Joko Widodo tweeted an image requesting prayers for the affected region and saying that he had asked relevant ministers and agencies to head to the region and assist with relief work.

The Indonesian Red Cross is deploying ambulances and water trucks to the region as well as distributing tarpaulins, blankets, sleeping mats and other supplies.

Getting enough supplies to the region will prove challenging, however. “The event has caused power outages and disruption of communication,” said Aulia Arriani, who added that the road from Poso, a town in central Sulawesi that could serve as a supply link to Palu, is damaged or blocked.

Efforts to contact officials and relief workers in Palu and surrounds proved difficult, as phones are either powered off or out of reach due to electricity outages or downed telephone masts.

Palu is a three hour flight across the Java Sea and Makassar Strait from Jakarta and is closer to the southern Philippines and eastern Malaysia than to Java, Indonesia’s most populous island. Damage to the airport and runway has so far hindered relief work and evacuations.

The earthquake and tsunami comes after a series of earthquakes in August that caused the deaths of at least 460 people on Lombok, a holiday island east of Bali, the main destination for tourists to Indonesia.

Indonesia, a 17,000 island, 3,000 mile long archipelago, sits on the Pacific Ring of Fire and is dotted with over a hundred active volcanoes. It has been hit with several deadly earthquakes in the years since late 2004, when a 9.1 magnitude earthquake off the coast of Sumatra, Indonesia’s westernmost island, send a huge tsunami barrelling across the Indian Ocean, killing over 230,000 people across the region, most of them Indonesians.